CVE-2026-68189

Status: UPDATED  |  Advisory ID: CVE-2026-68189

Key Details

Affected Products, Subsystems & Sectors

What to Know

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: hci_sync: Protect UUID list traversal

The hci_sync conversion moved class-of-device and EIR generation from an

HCI request built under hdev->lock to asynchronous command sync work.

The worker holds hdev->req_lock, but that lock does not serialize access

to hdev->uuids against add_uuid() and remove_uuid(), which update the

list under hdev->lock.

The following interleaving can therefore occur:

CPU0 (command sync work) CPU1 (management socket)

fetch uuid from the list

list_del(&uuid->list)

kfree(uuid)

read uuid->size

KASAN reports the resulting use-after-free:

BUG: KASAN: slab-use-after-free in eir_create+0xb8f/0xee0

Read of size 1 at addr ffff88810dbd8620 by task kworker/u17:0/87

Workqueue: hci0 hci_cmd_sync_work

Call Trace:

eir_create+0xb8f/0xee0

hci_update_eir_sync+0x1c0/0x330

hci_cmd_sync_work+0x13c/0x290

process_one_work+0x63a/0x1070

worker_thread+0x45b/0xd10

Allocated by task 86:

__kasan_kmalloc+0x8f/0xa0

add_uuid+0x18a/0x4b0

hci_sock_sendmsg+0x1033/0x1ea0

Freed by task 92:

__kasan_slab_free+0x43/0x70

kfree+0x131/0x3c0

remove_uuid+0x25e/0x560

hci_sock_sendmsg+0x1033/0x1ea0

Hold hdev->lock while generating and committing the class-of-device and

EIR snapshots. Release it before sending an HCI command, so controller

waits do not happen under the device lock. This protects all UUID list

walks in these paths and restores the serialization lost in the command

sync conversion. (NVD)

What to Do

Monitor Linux's web page for any future patch releases.

References